经济发达地区县域尺度土壤重金属污染区划

土壤重金属污染是社会关注的热点问题，而其区划是污染修复的基础。该文以地处经济快速发展地区的昆山市为例，综合运用地统计学、系统聚类分析、主成分分析等方法，以乡镇为基本单元，对研究区土壤重金属污染情况进行区划。结果表明：采用重金属污染状况结合孕污环境2次聚类的方法，研究区土壤重金属污染可划分为5个一级区和10个二级亚区。此分区体现了研究区土壤重金属污染空间分布状况和各乡镇孕污环境的空间差异，可对以后土壤重金属污染的控制及治理等相关工作借鉴。

Contamination zoning for soil heavy metal at county scale in developed area

Soil heavy metal contamination is a hot issue of social concern, and its regionalization is the basis of remediation. The integrated approaches of geo-statistical, cluster analysis, and principal component analysis were applied to conduct the soil heavy metals contamination zoning of Kunshan at county scale. The results of zoning included two grades, five soil contamination zones and ten soil contamination sub-zones according to cluster analysis of soil contamination and contamination-forming environment. The integrated approach of the two-step cluster analysis not only revealed the spatial differences of heavy metals contamination distribution in this area, but also further reflected the key factors which caused the contamination from outside of each unit. The research can provide some references to the heavy metal contamination control and remediation.